#include <bits/stdc++.h>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m;
    cin >> n >> m;
    vector<int> x(m), y(m);
    vector<int> row(n + 1),col(n + 1);
    for (int i = 0; i < m; i++) {
        cin >> x[i] >> y[i];
        row[x[i]]++;
        col[y[i]]++;
    }
    for (int i = 0; i < m; i++) {
        cout << x[i] << y[i];
    }
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        
    }

    cout << ans << endl;
    return 0;
}